The invention pertains to fluid couplings for closed fluid systems utilizing rupturable diaphragms which are automatically ruptured during interconnection of the coupling members.
Refrigeration systems basically consist of evaporator, condenser and compressor units interconnected by a conduit system. In many installations, such as air conditioning systems, it is desired to locate the evaporator, for instance, remotely from the condenser and compressor, and conduits of considerable length may be employed to interconnect these components. As the proper operation of refrigeration systems requires freedom of foreign matter from the systems, including water and water vapor, the components of such systems which are to be installed on site are often precharged with the refrigerant prior to shipment, and provided with sealed couplings to maintain the charge and integrity of the system prior to assembly. The components are provided with couplings which rupture the sealing diaphragms during interconnection of the coupling members, and upon completion of coupling assembly a flow path through the couplings is established, as well as a positive seal between the coupling members.
With sealed couplings of the aforementioned type the efficiency of fluid flow through the coupling is adversely affected by the presence within the coupling of the ruptured diaphragms, or blades or other structure used in the piercing of the diaphragms. U.S. Pat. No. 2,933,333 discloses a sealed coupling of the aforementioned type, and an annular passaged cutting sleeve is used to cut through the diaphragms, and hold the diaphragms, as much as possible, from the flow path. As the diaphragms, in accord with this patent, cannot be completely removed from the flow path a lowering of flow efficiency through the coupling occurs because of the restriction within the passage produced by the ruptured diaphragms. Also, with this type of coupling there is the possibility of ragged diaphragm edges occurring, and small pieces of the ruptured diaphragm may be freed within the conduit system, and create system malfunctioning.
The assignee's U.S. Pat. No. 3,202,442 utilizes a diaphragm rupturing blade or knife in conjunction with an annular blade support whereby the ruptured diaphragms are folded exteriorly and internally about the end of a male member extension. This construction has the advantage of substantially removing the ruptured diaphragms from the coupling flow path, but the cutting blade remains in the flow path creating a turbulence and a reduction of efficiency of flow through the coupling.
Couplings for closed fluid systems in accord with the known prior art are usually of relatively large size due to the internal structure, and at least one of the coupling members usually includes an outer end extending beyond the associated diaphragm whereby a recess is defined capable of accumulating foreign matter, which if not removed prior to coupling member assembly, may enter the refrigeration system, or adversely affect the sealing of the coupling members. Additionally, known seal couplings require significant amounts of metal, and are relatively complex in configuration, requiring relatively high manufacturing costs.